The M-1 Garand doesn't have any plastic. Therefore, it could never be a substitute.
The SKS is held in low esteem by many or most AR owners. The SKS was the 'sleeper gun' during the recent panic.

These rifles can't be pimped up very easily, and even with prices for 7.62x39 ammo back down to .25/rd., the SKS won't have much appeal.
Why put money into extra .223 (etc) ammo when it could have gone into AR accessories?